In general, a distribution board distributes electric currents to factories, or to large-scale residential buildings such as apartments while interrupting overcurrent, which prevents electric accidents and protects electrical loads.
A conventional distribution board includes a main circuit breaker in which electric power is led from a power source and breaks circuits when necessary; a plurality of main busbars that come into contact with the terminals of the main circuit breaker that are connected to loads; a plurality of circuit breakers for distributing electric power supplied from the main circuit breaker to the loads; and the branch busbar that comes into contact with the main busbars and the terminals of the circuit breaker for distribution therebetween such that the branch busbar distributes the route of current supplied from the main busbars.
To connect the main busbars and the branch busbar to each other using screws, the conventional distribution board requires tap work in which a hole is cut through a screw and a threaded surface is formed in the inner circumferential surface of the hole. In addition, the tap work requires specific facilities, thereby making the manufacturing process of the distribution board complicated, and mass production thereof difficult. Furthermore, the conventional distribution board requires manual labor, and thus it requires time and manpower to manufacture, thereby increasing manufacturing cost. In addition, when the conventional distribution board is required to be modified for adding circuits during the manufacturing, on-site installation and use of the conventional distribution board, the hole work and tap work of the main busbars and the branch busbar makes it impossible to efficiently perform the modifications.
In recent years, the busbar kit including the branch busbar has been used such that the branch busbar is not exposed to outside. However, since it is not easy to mount the busbar kit to the distribution board, it requires much working time and manpower. Further, if any one of the components mentioned above malfunctions, all components including an adjacent busbar kit are required to be removed from the distribution board, which makes it difficult to repair and replace the component that is out of order.